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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Posted on 11 May 2011 by John Cook

I was talking about climate to my dad last week (since the book launch, he will now talk to me about the subject) and I mentioned that 97% of climate scientists are convinced that humans are causing global warming. He registered great surprise at that statistic. "I thought it was more 50/50", he said. It made me realise just how good a job both the mainstream media and the fossil fuel funded disinformation campaign have done in confusing the public about the scientific consensus on global warming. At the same time, I was working on a consensus graphic (cribbed from the Guide to Skepticism) for a video presentation. So as a tool for anyone wishing to communicate the scientific consensus, I've added the following infographic to the Climate Graphics resource:

The 97% figure comes from two independent studies, each employing different methodologies. One study surveyed all climate scientists who have publicly signed declarations supporting or rejecting the consensus (Anderegg 2010). Another study directly asked earth scientists the following question "Do you think human activity is a significant contributing factor in changing mean global temperatures?" They found 97% of actively publishing climate scientists answered yes (Doran 2009). As "climate scientists actively publishing peer-reviewed research on climate change" doesn't really roll off the tongue, I abbreviated that down to "climate experts".

One feature of Doran's survey results is that while 97% of climate expert said "yes, humans are causing global warming", only 1% said "no, we're not". The other 2% were unsure:

Comments

Thanks for this, John - I'll be putting it to use quite shortly here at work!

I particularly like the way you've distinguished between the "No it's not" and the "I'm not sure" categories. It reinforces the message, that those who think humans are not responsible are a very tiny minority.

No need to be puzzled. Based on the few whose ideology I've been able to ascertain that 3% are hardcore right wing ideologues and quite a few ultra-fundamentalists. Both are predisposed to be anti-whatever their ideology/religion happens to be.

Sorry for critisizing you, but with this post you gave a fine example of an incorrect conclusion.
There is quite a difference between being a "cause" (your conclusion) and being a "contributing factor" (what was asked for).

David Horton
"Always puzzles me as to who the other 3% are!"
Its hardly unusual for there to be a few contrarians in any field. Older scientists who have not moved with the paradigm shift and perhaps a couple of younger ones who were drawn to the field to challenge the “orthodox”.

JoeRG, I'm sure everyone reading this has had the same thought, but I note that you missed out a significant word - the question included "significant contributing factor", which I would say nudges the brief headline "causing global warming" to an honest summation. We can't live our whole lives assuming the worst in human nature, no matter how strong the evidence seems to be.

les, you're right that's the important point. The question leaves no ambiguity that the experts think human actions affect the climate and therefore the implication is that through our actions we can do something to reduce the problems we face.

This quote from the paper is interesting
"The two areas of expertise in the survey
with the smallest percentage of participants
answering yes to question 2 were
economic geology with 47% (48 of 103)
and meteorology with 64% (23 of 36)."

Economic Geologists is understandible. Their field is digging stuff up out of the ground for profit. What Is less clear, and I have come across this before, is the disconnect between what climatologists think and meterologists. Oceanographers, geochemists etc are more likely to agree than the meteorologists.

I know who the 3 in 100 are! I have amused myself by calling them "The Three Stooges". This might be a bit harsh, even unfair, as the obvious stooges like Monckton, Plimer, etc. are not climate scientists. I was fond of the earlier infographic, but this one is more accurate in showing the grey, undecided, figures.

One may say, that we force climatic effects significantly in several cases -we do indeed- but without causing them, and therefore it is an inaccurate conclusion.

But, of course, this does not change the fact that we have a major impact on climate and that we have to act to minimize such effects.

It's just the "normal paranoia. Everyone in the universe gets that." (see D. Adams for details) It makes me wonder if some "sceptics/denialists" might use this inaccuracy as an argument against the consensus.

For pities sake, WAKE UP! All the while the argument regarding climate change is about whether the current warming is anthropogenic in origin or not, the action that is becoming more and more urgent gets put on the back-burner. Why? Because those politicians who, for reasons known to them and suspected by us, take either no action, or the absolute minimum necessary to keep their seats, the situation gets worse. The main problem is that the public sees the cause as important rather than the cure and who can blame them – it seems to be the only thing that the scientific community is interested in – this site included.

The current debate makes me think of a situation where a jumbo-jet is spiralling out of control while the captain and first officer are busy arguing as to the cause. Whether it was due to too much rudder or too low an airspeed is only of academic importance. (The flight-recorder recovered from the bottom of the resulting crater will determine the answer to that argument.) What they should be doing is getting the aircraft back under control (and organising an orderly queue for the toilet). they can leave the cause to be decided later. The evidence is not going to change in any detrimental way.

The argument should be centred on whether the world is warming or not and whether we should do whatever we can to offset that warming. Once the public sees that the debate is about the danger they and their offspring face and what we as a species should do to offset the warming that is causing that danger we might move forward. I.e. get the plane out of the spin and sod the cause for now. If greenhouse gases are a source of warming, they should be reduced - period. For now, it doesn’t matter whether they are the main cause or not.

We can, and most certainly will, debate the cause of the warming when it comes to dealing with the results of climate change. When we have to re-house tens of millions of Bangladeshi refugees, just to cite one example, and pay for the expense of same, the debate will get really serious. I rather think that the current batch of politicians who will be seen to have hindered remedial action will be called to account, as will their nations that failed to take that remedial action as a result. There will be many grandparents viewed with contempt by their grandchildren, not a nice situation for anyone and one to be avoided if possible, yet, unless they understand the science, they cannot be blamed for following their political leaders.

As things stand, the fossil fuel industry continues to make its corporate profits and its employees their bonuses while we all go to hell in a handcart. This side of the fence will be seen to be partially culpable, despite the clarity of the science. That clarity does not excuse the failure to redirect the debate towards the dangers of inaction; where the debate should really be. So I repeat: WAKE UP!

A) Given the ordinary operation of the climate system, anthropogenic emissions are a sufficient condition for climate change.

What is more,
B)Given the known current circumstances, anthropogenic emissions are the only sufficient condition that has actually occurred over the last century.

It follows that anthropogenic emissions are the cause of climate change in the most relevant sense of the term. It is also the most common sense of the term. Splitting hairs based on an obscure philosophical definition of causation simply causes confusion for those who don't understand your obscure usage, and adds nothing to clarity of public communication. The most likely consequence is 'deniers' picking up your claim and interpreting it as a denial of A and B above.

funglestrumpet @14, I've pinched myself and checked, and yes, I am awake! And being awake I've noticed that most deniers including those that dominate popular media and politics deny that CO2 levels have any significant effect on global temperatures. Therefore even if you could get them to agree that the Earth was warming catastrophically, they would not agree that reducing CO2 levels would effectively combat the warming, what ever the cause. So avoiding the argument about the climate effects of CO2 is no short-cut to effective political action. On the contrary, abandoning that argument is a guaranty that no effective action will be taken until it is too late for my children, and for theirs.

John, what about the Stanford study?! A third, independent review with even stronger conclusions (ie that not only are 97% of climate scientists convinced by the evidence but they are the more qualified scientists based on standard metrics)

Also I think this could be a great social networking piece - ask all SS readers (and I'm sure JR would get on board too) to make this their facebook picture. I hate social media as much as the next but that cr*p seems to influence public opinion (and at minimum would be worth the minimal effort.)

I suspect (opinion only, mind you) that it's because weather can only be predicted out to a short time frame. Most meteorologists don't have anything to do with long term predictions, like climate - perhaps they intuitively just don't see it as a possibility?

Harry Seaward @21, it is laughable desperation to suggest that the climatologists regularly publishing on climatology would not recognise the emissions of Green House Gases as the only current theory of anthropogenic influence on global climate having any credibility.

There also is the issue of whether people trust climate scientists to know more about climate than they trust economists to know about the economy. There has been a concerted attack on the credibility of climate science and climate scientists and I don't know if it has penetrated beyond the denialsphere into the general public.

These statistics are just wrong. I have previously attempted posted longs lists of scientists and their positions who oppose the AGW hypothesis, but my posts are apparently deleted by the editor. Would you like me to post them again? These lists would certainly be "on-topic" for this thread.

00

Response:

[DB] Poptech's list has been done ad infinitum on the Meet The Denominator thread. Please refrain from reposting them here.

Tom @ 23,
I guess you forgot about your boys at the IPCC and this statement:

"From new estimates of the combined anthropogenic forcing due to greenhouse gases, aerosols, and land surface changes, it is extremely likely that human activities have exerted a substantial net warming influence on climate since 1750."

The letter to UN Secretary Ban from scientists demanding disbanding of the UN IPCC is not posted at Meet the Denominator.

The Open Letter with long list of scientists to President Obama in the New York Times, to inform him he is wrong about his stated concern about global warming, this letter and list is not posted at Meet the Denominator.

The Manhattan Declaration on Climate Change and its long list of scientists and others is not posted on your site.

The quotes I listed from many climate scientists including a 38 year veteran analyst at US EPA is not on your site.

So, why did you delete these?

00

Response:

[DB] Merely copy-pasting articles and/or links amounts to copy-vomit; as such it adds nothing to the discussion. Without adding in context as to WHY you feel the materiel is important and HOW you feel it fits in or needs to be accounted for, then it adds nothing to the discourse here.

If your intent is to not be merely disruptive, then please adjust your comment construction accordingly. Thanks!

More than 60 prominent German scientists have publicly declared their dissent from man-made global warming fears in an Open Letter to German Chancellor Angela Merkel. (Translated letter copied below) The more than 60 signers of the letter include several United Nations IPCC scientists. The letter urged Chancellor Merkel to "strongly reconsider" her position on global warming and requested a "convening of an impartial panel" that is "free of ideology" to counter the UN IPCC and review the latest climate science developments.

To the attention of the Honorable Madam Angela Merkel, Chancellor of Germany

When one studies history, one learns that the development of societies is often determined by a zeitgeist, which at times had detrimental or even horrific results for humanity. History tells us time and again that political leaders often have made poor decisions because they followed the advice of advisors who were incompetent or ideologues and failed to recognize it in time. Moreover evolution also shows that natural development took a wide variety of paths with most of them leading to dead ends. No era is immune from repeating the mistakes of the past.

Politicians often launch their careers using a topic that allows them to stand out. Earlier as Minister of the Environment you legitimately did this as well by assigning a high priority to climate change. But in doing so you committed an error that has since led to much damage, something that should have never happened, especially given the fact you are a physicist. You confirmed that climate change is caused by human activity and have made it a primary objective to implement expensive strategies to reduce the so-called greenhouse gas CO2. You have done so without first having a real discussion to check whether early temperature measurements and a host of other climate related facts even justify it.

A real comprehensive study, whose value would have been absolutely essential, would have shown, even before the IPCC was founded, that humans have had no measurable effect on global warming through CO2 emissions. Instead the temperature fluctuations have been within normal ranges and are due to natural cycles. Indeed the atmosphere has not warmed since 1998 - more than 10 years, and the global temperature has even dropped significantly since 2003.

Not one of the many extremely expensive climate models predicted this. According to the IPCC, it was supposed to have gotten steadily warmer, but just the opposite has occurred.

More importantly, there's a growing body of evidence showing anthropogenic CO2 plays no measurable role. Indeed CO2's capability to absorb radiation is already exhausted by today's atmospheric concentrations. If CO2 did indeed have an effect and all fossil fuels were burned, then additional warming over the long term would in fact remain limited to only a few tenths of a degree.

The IPCC had to have been aware of this fact, but completely ignored it during its studies of 160 years of temperature measurements and 150 years of determined CO2 levels. As a result the IPCC has lost its scientific credibility. The main points on this subject are included in the accompanying addendum.

In the meantime, the belief of climate change, and that it is manmade, has become a pseudo-religion. Its proponents, without thought, pillory independent and fact-based analysts and experts, many of whom are the best and brightest of the international scientific community. Fortunately in the internet it is possible to find numerous scientific works that show in detail there is no anthropogenic CO2 caused climate change. If it was not for the internet, climate realists would hardly be able to make their voices heard. Rarely do their critical views get published.

The German media has sadly taken a leading position in refusing to publicize views that are critical of anthropogenic global warming. For example, at the second International Climate Realist Conference on Climate in New York last March, approximately 800 leading scientists attended, some of whom are among the world's best climatologists or specialists in related fields. While the US media and only the Wiener Zeitung (Vienna daily) covered the event, here in Germany the press, public television and radio shut it out. It is indeed unfortunate how our media have developed - under earlier dictatorships the media were told what was not worth reporting. But today they know it without getting instructions.

Do you not believe, Madam Chancellor, that science entails more than just confirming a hypothesis, but also involves testing to see if the opposite better explains reality? We strongly urge you to reconsider your position on this subject and to convene an impartial panel for the Potsdam Institute for Climate Impact Research, one that is free of ideology, and where controversial arguments can be openly debated. We the undersigned would very much like to offer support in this regard.

Respectfully yours,

Prof. Dr.rer.nat. Friedrich-Karl Ewert EIKE

Diplom-Geologe

Universität. - GH - Paderborn, Abt. Höxter (ret.)

#

Dr. Holger Thuß

EIKE President

European Institute for Climate and Energy

http://www.eike-klima-energie.eu/

00

Moderator Response: Your "prominent German scientists" are not necessarily all "climate scientists" as are the ones that are the topic of this post. It would be more relevant if you linked to the list of those 60 scientists; sorry, I can't read German, so I can't find that list on that site you linked to.

@30, Bud: Hmm, a letter from a non-expert (Holger Thüss studied law and history) doing a full Gish Gallop? Interesting.

The letter says he's president of an institute on climate and energy? Sounds mighty impressive and important, but is it really? Well, it turns out that EIKE is only the 'scientific' front of the libertarian lobby organisation CFACT.

In other words: it's only one of the many libertarian propaganda outlets pretending to produce 'real science'. It's really an astroturf operation.

Why should a letter of a front group for a libertarian lobby organization, filled with long debunked nonsense as documented by Skeptical Science, be listed on this very same site?

Bud, you need to carefully read and understand the difference between "climate experts" and "scientists" : the former are the latter, but the latter are not necessarily the former. This is so obviously the case with the majority of those on any of your lists (most of whom have no connection with Climatology in any shape or form), that it is surprising that you think they have any relevance to this topic. This is especially so when you think of how many scientists there are in the world and how many have signed these petitions, letters, etc. Here's a hint : the fact that you can mention small numbers (in the same way as is done in that little list shown elsewhere on here, to which link you were referred) - and think they mean anything in comparison to the complete list of papers, studies, scientists, etc - is a sure sign of desperation.

However, if you do insist on relying on your beliefs being determined by the smallest number, I'm sure you will be backing these 100 scientists :

"I am skeptical of claims for the ability of random mutation and natural selection to account for the complexity of life. Careful examination of the evidence for Darwinian theory should be encouraged."

Bud, you keep on posting lists of people's opinions. You should instead try science papers published in peer-reviewed science publications. The sicentists whose opinions have been the subject of this post publish in the field regularly, that's why their opinions are relevant. Op-ed letters from astroturf groups don't carry much weight really.

I've always supposed that both the Anderegg and Doran numbers are a little bit skewed in favor of the skeptics. If I'm not mistaken, both of these papers relies on scientists voluntarily responding to the study. I would suppose that a skeptical climate scientist (your Spencer's and your Lindzen's) are going to be much more likely to respond. Whereas the larger body of climate scientists are going to be more inclined to opt out.

I bet the real numbers are in excess of 99% believing climate change is caused by humans.

Bud... I would also suggest that maybe your 61 German scientists are lying to you. They state in their letter that "... the global temperature has even dropped significantly since 2003. [added emphasis]

Analysis by The Carbon Brief found that the ten authors are responsible for 186 of the over 900 peer-reviewed papers skeptical of man-made global warming.

The most prolific climate-skeptic author on the list was Sherwood B. Idso, president of the Center for the Study of Carbon Dioxide and Global Change, a think-tank which the Carbon Brief said has been funded by ExxonMobil. Idso authored or co-authored 67 of the 938 papers analyzed, or seven percent of the total.

The second most cited is Patrick J. Michaels, with 28 papers. Michaels has said that he receives about 40% of his funding from the oil industry.

Researchers Willie Soon and John R. Christy are both affiliated with the George C. Marshall Institute, which receives Exxon funds, the website found. Another author, Ross McKitrick, is a senior fellow at the Fraser Institute, which also benefits from Exxon funding, the Carbon Brief said.

Eight of the ten have direct links to ExxonMobil, the analysis found, while a ninth researcher, Bruce Kimball, is linked to the oil giant because all of his papers were co-authored with Sherwood Idso.

I still haven't found evidence that the Doran survey was peer reviewed. IMHO the survey was designed to get the desired results.

First,the researchers excluded from their survey the thousands of scientists most likely to think that the Sun, or planetary movements, might have something to do with climate on Earth (i.e., solar scientists, space scientists, cosmologists, physicists, meteorologists and astronomers).

They sent their survey to disciplines like geology, oceanography, paleontology, and geochemistry.

Second, scientific accomplishment or academic credentials were not factors in who could answer. Surveyees were chosen by by their place of employment (an academic or a governmental institution). About 1,000 of those surveyed did not have a PhD, and some did not have a master’s degree.

3,146 (30.4%) responded to the two questions:

1. When compared with pre-1800s levels, do you think that mean global temperatures have generally risen, fallen, or remained relatively constant?

2. Do you think human activity is a significant contributing factor in changing mean global temperatures?

Of the overall respondees 90% answered RISEN to Question #1. That is surprising unless the ambiguity of the question caused the 10% to reach further back in history.

For Question #2, 82% of the earth scientists replied that that human activity had significantly contributed to the warming. Again, the amibiguity of the question comes into play. Since most skeptics I know (including me), believe that human activity is a contributing factor, their answer depends on the definition of "significant". The value of the word significant should have been defined.

However, since the 82% figure might not be convincing enough, subsets were created to achieve the numbers. Cuts were made leaving only climate change scientists. 75 out of 77 scientists (97%) were left endorsing the anthropogenic global warming hypothesis.

The authors of the paper were honest in describing their methods. However, when the 97% number is touted as the gospel it is misleading to say the least.

Harry @ 41... If you'll note, there are two papers referenced here. Each used different methods to come to their conclusions. Each got near identical results. That's generally an indication that the results are robust.

The "skeptics" have yet to put forth any study showing anything to the contrary. They've only used the tactic of big numbers with no denominator (i.e., 31,000 "scientists" without saying how many "scientists" there are).

The Anderegg paper is poorly done.
1. Google Scholar instead of an academic database was used.
2. The search was only done in English, despite the global nature of climate science.
3. Names are incorrect.
4. Job titles are wrong.
5. The number of publications and citations is incorrect.

Let's not forget the Oreskes study, which was subsequently confirmed by the Peiser study, despite Peiser's aim to disprove Oreskes. Neither found any valid peer-reviewed studies rejecting the consensus in a sample of approximately 1,000 searched (though it took Peiser a while to admit this).

Really, how many studies and surveys confirming the consensus does it take to convince you, Harry?

Please list for us all the professional scientific societies of the same standing as the American Meteorological Society (for example) who state that human emissions of GHGs are not contributing to global warming.

You're digging very hard, Harry, but I think you'll find more of the type of gold you're looking for in Poptech's hill. Just once I want to see a self-identified "skeptic" go after another self-identified "skeptic". Just once.

Again, Harry... Where is the information showing that the studies are in error? Where is the study showing that a larger number of climate scientists doubt AGW? You're not putting forth any reasonable refutations of these two papers.

RE: Anderegg...
1. Has no bearing on the results.
2. Has no bearing on the results.
3. Has no bearing on the results.
4. Has no bearing on the results.
5. Also, has no bearing on the results.

The statistical margin of error in both of these papers is small due to the number of respondents.

Harry Seaward, rather than copying the views of a certain individual who maintains a little list of what he considers to be 'peer-reviewed' papers against AGW Alarm (whatever that means), why not actually search out the facts for yourself.

Here you can count up to fifty, to find all the scientists who go against the consensus.
(Actually, the number doesn't reach fifty but some will prefer any little number to the thousands who agree with the consensus. Why is that, I wonder ?)

Also, Harry Seaward can you confirm your backing for the 100 scientists (i.e. twice as many as those mentioned in my last link here) I mentioned in previous post.

Danno @ #3
You are stating that the source of funding for research influences the scientist's results.

"the 1% is a handful of scientists funded by the fossil fuel industry?"

I see this a lot when referring to skeptics. Not so much when referring to warmists. But, if you are right, then all sources of all funding to all scientists must be considered. And, you are thus implying that all scientific research is inherently flawed based on funding.